Fluid compressor controlling valve



Aug. 9, 1932. E. E, HEWITT 1,870,843

FLUID COMPRESSOR CONTROLLING VALVE Filed March 15, 1930 "Figl so ELLIS E.HEW|TT BY%W . ATTO R NEY Patented Aug. 9, 1932 4 i UNITED STATES ELLIS E. HEWITT, OF EDGEWOOD, PENNSYLVANIA, ASSIGNOR'TO THE WESTINGHOUSE rharizlvror fice;

AIR BRAKE COMPANY, OF WILMERDING, PENNSYLVANIA, A CORPOR. ATION- 0F PENNSYLVANIA FLUID COMPRESSOR CONTROLLING VALVE Application filed March 15, 1930. Serial No. 436,048.

26, 27, and 28 of the same diameter, and a This invention relates to fluid compressors, and more particularly to a compressor of the type employed on locomotives for compressing air for use in the fluid pressure valve brake system.

The locomotive type of fluid compressor employs a main valve for controlling the supply and exhaust of steam to and from the steam cylinders of the compressor, and a reversing valve for controlling the steam for operating the main valve.

The principal object of my invention is to provide an improved piston valve construction for a fluid compressor, in which means are provided for obviating the danger of breaking or damaging the piston rings of the piston valves as the piston valves are being inserted in their bushings.

In the accompanying drawing; Fig. 1 is a sectional view of a main valve construction embodying my invention; and Fig. 2 a diagrammatic sectional view of a compound steam driven fluid compressor, showing the operative association of the main valve with the compressor.

As shown in Fig. 2 of the drawing, the fluid compressor comprises a steam cylinder section 1, an air cylinder section 2, an intermediate section 3, a valve head 4, and an air cylinder cover plate 5. The section 1 has a high pressure steam cylinder 6, and a low pressure steam cylinder 7 containing the respective steam pistons 8 and 9. The air cylinder section 2has a low pressure air cylinder 10 and a high pressure air cylinder 11 containing the respective air pistons 12 and 13. The high pressure steam pistonS is connected to the low pressure air piston 12 by a piston rod 14, and the low pressure steam piston 9 is connected to the high pressure air piston 13 by a piston rod 15.

In axial alinement with the steam piston 8 is a reversing valve 16 which may be of the piston type, having piston heads 17, 18, 19, and 20. S'ecured to the reversing valve 16 is a reversing rod 21, the lower .end of which extends into a bore 22 in the piston rod 14 and is provided with a button 23.

The main valve comprises a hollow onepiece casting 24, having piston heads 25,

piston head 29 of greater diameter than the other piston heads.

The piston heads 25 to 28 operate in a single bushing 30, and the chamber at the outer face of piston head 25 is closed by a cover plate 31, which is secured to the valve casing by bolts 32. The piston head 29 operates in a detachable cover plate 33, in which is mounted a separate bushing 34, for the piston head 29, the cover plate 33 being secured to the valve casing by bolts 35.

In assembling the main valve, the cover plate 33 being removed, the valve 24 is entered into the bushing 30 at the right hand end. The piston head 25 is entered first, and the piston rings of the piston head can be seen and guided into place in the bushing 30, the movement being facilitated by providing a taper 36 at the right hand end of the bushing. The piston heads 26, 27 and 28 are then successively entered into the bushing 24. The cover plate 33 is now fitted over the piston head 29, and then the cover plate is secured to the valve casing by means of the bolts 35.

By means of this construction, the piston rings of the several piston heads of the main valve are fitted into the bushing without danger of breaking the piston rings, since each individual piston head with its piston rings may be seen and guided into place.

It is not deemed necessary to described in detail the operation of the main valve 24 to control the admission and exhaust of steam to and from the steam cylinders of the compressor, nor the operation of the reversing valve 16 to supply and exhaust steam to and from the piston head 29 so as to eflect the operation of the main valve 24, since such operation corresponds with thatof previous fluid compressors of this type, and since the invention relates to features of the main valve construction not involving the operation of the compressor. While one illustrative embodiment of the invention has been described in detail, it is not my intention to limit its scope to that embodiment or otherwise than by the terms of the appended claim.

Having now described my invention, what Hit I claim as new and desire to secure by Letters Patent, is:

A "steam controlling valve mechanism for a steam engine comprising a casing, a bushing in said casing,'a controlling valve having a plurality of piston heads of the same diameter, and each provided with piston rings, said piston heads being mounted to recipro cate in said bushing, an additional piston head of larger diameter associated with said valve, a hollow cover plate detachably secured to said casing, and a bushing in said cover plate in which said piston head of larger diameter is adapted to reciprocate. V V V In testimony whereof I have hereunto set my hand, this 12th day' of March, 1930.

' ELLIS E. HEWITT. 

